Instantly AirMail vs Premium Inboxes
Instantly AirMail (AirMail SMTP inboxes on Instantly infrastructure) and Premium Inboxes (Google & Microsoft mailboxes, done-for-you) are both popular cold email infrastructure picks. For 30 mailboxes on 10 domains, Premium Inboxes is cheaper at $113.72/mo vs $128.72/mo for Instantly AirMail, a difference of $15.00 a month ($180 a year).
Last updated 2026-11-02 · list prices, monthly billing
Instantly AirMail
Premium Inboxes
Verdict by use case
Side by side
| Instantly AirMail | Premium Inboxes | |
|---|---|---|
| Mailbox type | Shared SMTP | Google/Microsoft reseller |
| Platform | SMTP | GoogleMicrosoft |
| Per mailbox / month | $4.00 Listed as $4 per inbox, no minimum; Instantly's page does not state the billing period. Runs on Instantly's own infrastructure, not Google or Microsoft. | $3.50 1-249: $3.50; 250-1,249: $3.00; 1,250+: $2.80. Annual saves 20%. |
| 30 mailboxes / month | $120 | $105 |
| + 10 domains / month | $8.72 * | $8.72 * |
| Total / month | $128.72 | $113.72 |
| Minimum | None | No monthly commitment |
| Warmup | Not stated | No |
| Sending cap | None published | None published |
| Price source | Provider page | Provider page |
* Reference .com price used (provider domain price not published).
Frequently asked questions
Is Instantly AirMail cheaper than Premium Inboxes?
For 30 mailboxes + 10 domains on monthly list prices, Premium Inboxes is cheaper: $113.72/mo vs $128.72/mo (checked 2026-11-02).
What's the difference between Instantly AirMail and Premium Inboxes?
Instantly AirMail: AirMail SMTP inboxes on Instantly infrastructure, $4.00 per mailbox, minimum none, warmup not stated. Premium Inboxes: Google & Microsoft mailboxes, done-for-you, $3.50 per mailbox, minimum no monthly commitment, warmup no.
Which is better for cold email, Instantly AirMail or Premium Inboxes?
On price, Premium Inboxes wins for a 30-inbox setup. Beyond price, compare platform (SMTP vs Google/Microsoft), minimums and warmup. MailboxWatch doesn't test deliverability.